1. Field of the Invention
The disclosure relates generally to a system and method for indicating receipt paper supply in a receipt printer, and more particularly to a system and method for indicating low paper conditions in a receipt printer.
2. Description of the Background
Traditionally, receipt paper rolls are marked with a pink stripe near an end of the paper (i.e., the end of the length of paper comprising the paper roll). This pink stripe is used to alert an operator that the roll is nearing the end of its supply, and needs to be replaced soon.
Instead of using this pink stripe however, some commercial users of receipt paper employ low paper sensing devices (i.e., low paper scanners) that detect when receipt rolls are nearing the end of their supply. Commercial users, such as high-end stores that do not want to give out a receipt that includes a pink stripe and stores with unattended and self-checkout stations, often fall into this category. The low paper scanners used may be mechanical, such as limit switches, or optical, such as single channel reflectors. A drawback to these types of scanners is that they must be mechanically adjusted by a user to compensate for an outer diameter of a core portion of the paper roll, paper thickness, and desired length of remaining paper to set the alert. Since core portions, paper thickness, and desired length of remaining paper is variable among a set of customers, initial adjustment can be time consuming and inaccurate.
Since different receipt paper users desire different “low points” on the paper portion of the roll (typically anywhere from 1-15 feet from the end of the roll), it is impossible for receipt paper roll manufacturers to provide determine a uniform point for marking on the paper roll. Thus, manufacturers sell paper rolls that are low point marked at over different lengths, typically from 5 to 15 feet from the end of the roll. This variation, particularly in cases where one store uses rolls with different low point markings for different applications, can lead to confusion, and usage of rolls with undesirable low point markings for a specific application.
As such, a low paper sensing system that can both conveniently adjust to variation in core outer diameter and paper thickness and be conveniently adjusted to match a desirable low point for a specific user/application, is desirable.